This phase III trial compared 2 different Lenalidomide-containing induction regimens and 2 different Lenalidomide-containing maintenance regimens in an elderly community-based NDMM population. MPR prolonged PFS by approximately 5 months, yet the higher incidence of hematologic toxicity should be carefully considered. The addition of low-dose prednison-e to standard lenalidomide maintenance reduced the risk of death/progression by 20%, with a good safety profile. Updated results will be presented at the meeting.

In this integrated analysis, single-agent ixazomib maintenance therapy following an ixazomib-based induction regimen was associated with deepening of responses and good long-term outcomes in NDMM pts not undergoing ASCT. Single-agent ixazomib is feasible for long-term administration, with limited new-onset grade ≥3 AEs. These outcomes appear similar to other studies involving maintenance approaches in NDMM and support the ongoing phase 3 investigation of ixazomib maintenance therapy.

Prophylactic use of 12 weeks levofloxacin for patients undergoing treatment for active myeloma significantly reduces febrile episodes and deaths without increasing healthcare associated infections or carriage of key nosocomial pathogens. The value of adding SMZ-TMP to levofloxacin and for periods greater than 12 weeks needs to be explored in future trials.

We would conclude that MRD is a particularly powerful predictor of outcome in the maintenance setting and is clearly a desirable therapeutic goal in this patient group. The hazard ratio of 0.2 demonstrated here appears superior to those demonstrated in previous studies examining post induction or ASCT time-points. Approximately one third of MRD-positive patients receiving maintenance became MRD-negative and maintenance therapy also results in a decrease in disease levels in those patients remaining positive. These results support the role of MRD monitoring in assessment of the efficacy of different maintenance/consolidation strategies within clinical trials. In the longer term, a stratified approach to treatment based on sequential MRD assessments is feasible. The predictive ability of MRD during maintenance will be assessed with respect to overall survival when the primary endpoint matures in September 2017 and presented at the meeting.

This is the largest study of MRD monitoring in MM based on the total number of samples analyzed (n=1,134). Our results show that NGF-based MRD assessment is feasible in large multicenter clinical trials, is highly-sensitive, and allows the identification of hemodiluted BM samples inadequate for MRD assessment. Risk of relapse among MRD-negative patients was remarkably reduced (3%), and was particularly related to the reappearance of extramedullary plasmacytomas, which urges the need for combined cellular and imaging MRD monitoring in these patients; by contrast, even MRD levels as low as 10-5 and 10-6 conferred significantly inferior PFS. Overall, this study defines MRD-negativity as the most relevant clinical endpoint for both standard- and high-risk transplant-eligible MM patients.